Radio-frequency identification (RFID) is a data collection technology that uses radio-sensitive tags for storing data. Typically, the data indicates properties of an asset or assets to which the RFID tag corresponds. For instance, an article of clothing may have attached thereto an RFID tag uniquely identifying the article, including properties (model, color, size, etc.) thereof. RFID tags, which are also commonly referred to as transponders, typically comprise two parts. The first part is an integrated circuit for storing and processing data, modulating and demodulating radio-frequency (RF) signals, and performing other specialized functions. The second part of the RFID tag is an antenna that provides the means for the integrated circuit to transmit its stored data to an RFID reading device (also referred to herein as an interrogator). An RFID reading device can be incorporated into a larger mobile unit referred to herein as an RFID reader, scanner, or portable data terminal.
Radio-frequency identification readers have the ability to receive and decode tags from many different orientations and distances. This is one of the great advantages of RFID technology over, for instance, barcode-reading and other technology that requires line-of-sight. However, with the convenience afforded by RFID reading comes the disadvantage of tag pollution when RFID tags are read in a highly populated (by RFID tags) space. RFID readers generally do not discriminate between the tag data received from RFID tags. Tag pollution refers to tendency for RFID readers to receive (and possibly decode) tag data from RFID tags which are extraneous—that is, outside of the scope of what is desired to be scanned and observed. Furthermore, radio-frequency reflection, in which signals tend to reflect off of metallic materials, such as inventory fixtures, equipment, and even other RFID tags, can also be problematic. It is in some cases impractical and/or virtually impossible to scan only a particular area, region, or subset of tags (from e.g. clothes stacked on a rack), or even to know precisely from which direction the reader is attempting to read, making asset tracking, such as for inventory and other purposes, difficult.
Current systems in place can take advantage of simple programming logic to help mitigate this issue, in which the reader is preprogrammed, such as with predetermined list(s) of expected serial numbers or electronic product codes associated with RFID tags. The predetermined lists are created by an inventory tracking/management system and are based on knowledge the system possesses as to which inventory exists. Current RFID technology in the retail space is thereby reduced to no more that a ‘verification counting system’, in which only received tags on the predetermined list are ‘counted’ and compared to an expected count in an inventory database.